In theory, an integrator is lossless but in practice the integrator is not. Typically, a resistor is inserted into the integrator to reduce a loss factor q. By reducing the loss factor q, the Q value of the integrator can be optimized. Another factor that affects the loss factor q and the Q value is temperature variation of the integrator. The resistance value of the resistor changes in response to temperature variation. One previous method uses a digital-to-analog converter (DAC) to adjust the resistance value of the resistor. However, the DAC method typically matches the Q value at one temperature. If the temperature changes, the Q value of the integrator also changes.
Desirable in the art is an improved temperature compensated circuit that can improve the Q value of the integrator with temperature variation.